Method of producing molded products from stripped roofing material

ABSTRACT

A method of converting stripped roofing material into a useful product comprising feeding roofing material removed during repair or reroofing of a building roof into a shredder introducing particles of material from said shredder together with particles of thermoplastic material and a particulate filler material into a high intensity mixer to form a batch of material to be mixed, intensely mixing said batch of material to produce a heated mass of hot particles of roofing material and filler material coated with molten thermoplastic, then molding said heated mass under pressure into a desired end product. The invention also includes products produced utilizing said stripped roofing material.

FIELD OF THE INVENTION

This invention relates to the handling of stripped roofing material suchas shingles and tiles which are removed and replaced during the repairor reroofing of a building.

BACKGROUND OF THE INVENTION

At present, when a roof is to be repaired or reroofed, the old ordamaged shingles or tiles, a large percentage of which are formed ofasphalt are simply waste products which have to be trucked to a dump andunloaded. This disposal operation involves both transportation costs anda charge by the dump for accepting this waste material.

SUMMARY OF THE INVENTION

It is the object of the present invention to convert such old shinglesor tiles into useful products. It is a further object of the inventionto enable such conversion to be effected at the site of the shingle ortile removal.

A still further object is to convert such stripped roofing material intobuilding products or elements which can be used at the removal site.

More particularly, according to the invention, the stripped roofingmaterial is first shredded, then intensely and intimately mixed withparticles of thermoplastic material and a particulate filler material toheat the mixture to bring the thermoplastic material to a viscous moltenstate whereby the molten thermoplastic material coats the hot shreddedroofing particles and the hot filler particles to produce a hot moldablemass, then compression molding said mass to form a desired end productor products.

Because the process involves only a shredder, a motor driver mixer and acompression mold, the equipment necessary to carry out the method canreadily be mounted on a truck, tractor or other vehicle and transportedto the job site when the process can be carried out.

While many different products may be so formed depending on the moldused, examples of such products include interlocking blocks or bricksfor driveways, walkways and the like, bricks or blocks for edgingdriveways, walkways or forming borders for planting areas, or blocks forforming patios and the like.

It is therefore another aspect of the invention whereby the use of themobile shredder, mixer, and the selected compression mold can produce onthe job site a product which can be advantageously used at that site.

For example, the resulting products such as interlocking blocks or tilescan then be used to provide an interlocking driveway or walkway toenhance the site.

It will be understood that, while not taking full advantage of theinvention, the processing of the stripped roof material may be done awayfrom the site, even when such stripped roof materials are no longerwaste materials to be carted to the dump. Instead they are convertedinto valuable, useful products.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective diagrammatic view illustrating the processing ofroof shingles by on site vehicle transported processing equipment inaccordance with the invention.

FIG. 2 is a process flow diagram illustrating the conversion of the roofmaterial into a final product.

DETAILED DESCRIPTION ACCORDING TO THE PREFERRED EMBODIMENTS OF THEPRESENT INVENTION

With reference to FIG. 1, there is illustrated a house 1 whose roofingmaterial, for example asphalt shingles 2, are being removed prior toreroofing.

The equipment for converting the waste shingles shown comprises avehicle mounted shredder 3 and a motor driven high intensity mixer 4transported to the house site by truck 5. A trailer 6 is shown ascarrying the vehicle mounted compression mold 7 which will be selectedto form the desired product at the site. The discarded roofing piecessuch as the shingles 2 are shown being delivered into the shredderhopper 8 by a belt 9 although they could be simply thrown into thehopper 8.

The shredded particles or pieces from the shredder 3 together withparticles of thermoplastic material and a filler material are then fedas a batch into the mixer hopper 11 of the type in which motor drivenhigh speed rotating blades cause the particles of material introducedinto the mixer cylinder to collide at high speed and to impinge on thewall of the mixer giving rise to inner friction heating raising thetemperature of the particles until the thermoplastic particles reach amolten temperature. At this point, the molten thermoplastic materialcoats and sticks to the hot roofing and filler particles to convert thebatch 10 of the particulate material into a hot mass with the hotparticles of roofing and filler coated and bound together by thethermoplastic material whereupon they are discharged out the dischargegate 12 of the mixer and transferred to the compression mold 7. This hotmass is then molded under pressure into the desired end products such asthe interlocking brick or block 13 illustrated in FIG. 2.

If there is not enough power available from the house mains to drive theshredder or mixer motor 14, for example, then portable electricalgenerating equipment (not shown) can be provided.

The preferred filler material to be mixed with the shredded wasteroofing material such as shredded asphalt shingles is sand which isreadily available. However, other filler material such as waste slagparticles, fly ash could also be used. The thermoplastic material can beany number of thermoplastics such as recycled or waste particles of PVC,polyethylene, polypropylene, polyethylene terephthalate (PET), nylon,ABS, and the like, preferably those thermoplastic particles that haverelatively low melting points.

While shingles of asphalt material are very prevalent, the waste roofingmaterial may comprise wood shingles, old roofing tar paper, or otherbituminous material and can include broken tiles or the like.

The mixture of shredded roofing material, particles of thermoplasticmaterial, and filler material may vary over a wide range. For example,the batch may comprise by weight 30% to 50% roofing particles, 30% to50% filler material such as sand, and 10% to 40% of thermoplasticparticles. Preferably the thermoplastic material comprises from about20% to 40% of the mixture and the balance roughly an even blend ofroofing particles and filler or sand.

By handling the waste roofing material at the job site, all costs oftransporting waste material and paying for its acceptance into a dumpare eliminated yet at the same time useful end products are produced.These end products which may be interlocking bricks 12 such asillustrated or any other number of products such as patio tiles or thelike will comprise very durable products in which the particulatematerial comprising the roofing particles and the filler particles arebound together into a compacted mass as a result of being molded underpressure causing the molten plastic material to encapsulate and stronglybind together the particulate material.

While the full benefits of the invention are obtained by transportingthe shredder, mixer and compression molder to the job site, it will beunderstood that the waste roofing materials may themselves betransported to a plant where the process is carried out to recoveruseful end products from this waste material. Alternatively, the roofingmaterial could simply be shredded at the job site and transported to aplant where it could be used to form the desired end products.

It will be understood that various other alternatives and arrangementsmay be made without departing from the scope of the appended claims.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. A method of convertingstripped roofing material into a useful product comprising feedingroofing material removed during repair or reroofing of a building roofinto a shredders, introducing particles of material from said shreddertogether with particles of thermoplastic material and a particulatefiller material into a high intensity and intimately mixer to form abatch of material to be mixed, intensely mixing said batch of material,comprising said particles of thermoplastic material, said particles fromsaid shredder and said particulate filler material, in order to heat themixture by friction, bring, said thermoplastic material to a viscousmolten state, to produce a heated mass of hot particles of roofingmaterial and filler material coated with molten thermoplastic, thenmolding said heated mass under pressure into a desired end product.
 2. Amethod as claimed in claim 1 in which said shredded roofing materialincludes particles of asphalt shingles.
 3. A method as claimed in claim1 in which said batch of material comprises by weight from about 30% to50% of roofing particles, 30% to 50% of filler particles, and 10% to 40%of thermoplastic particles.
 4. A method as claimed in claim 3 in whichsaid shredded roofing particles include particles of asphalt roofingmaterial.
 5. A method as claimed in claims 3 or 4 in which said fillermaterial comprises sand.
 6. A method as claimed in claims 3 or 4 inwhich said thermoplastic particles are particles of recycledthermoplastic material.
 7. A method as claimed in claims 3 or 4 in whichsaid filler particles are sand and said thermoplastic particles areparticles of recycled thermoplastic material.
 8. A method as claimed inclaims 1, 2 or 3 which is carried out at the site at which said roofingmaterial is stripped.
 9. A method of recovering value from materialsstripped from the roof of a building during roof repairs or reroofing,said method comprising transporting vehicle mounted equipment includinga shredder, a high intensity mixer, and a compression mold to the siteof said building, feeding said stripped roofing material into saidshredder to produce shredded roof particles or pieces, feeding said roofparticles or pieces into said mobile mixer together with particles ofthermoplastic material and a particulate filler material to form a batchmixture, intensely mixing said batch mixture in said mixer to produce aheated mass of hot particles of roofing material and filler material,coated and bound together with molten thermoplastic, then molding saidheated mass under pressure into a desired end product.
 10. A method asclaimed in claim 9 in which said shredded roofing material includesparticles of asphalt shingles.
 11. A method as claimed in claim 9 inwhich said batch of material comprises from about 30% to 50% shreddedroofing particles, 30% to 50% filler particles, and 10% to 40%thermoplastic particles, said percentages being by weight.
 12. A methodas claimed in claim 11 in which said shredded roofing particles includeparticles of asphalt roofing.
 13. A method as claimed in claims 11 or 12in which said filler particles comprise sand.
 14. A method as claimed inclaims 11 or 12 in which said thermoplastic particles are particles ofrecycled thermoplastic material.
 15. A method as claimed in claims 11 or12 in which said filler particles are sand and said thermoplasticparticles are particles of recycled thermoplastic material.